You should contact the folks at Wolfram, they're very helpful people and they'll probably help you with this if there's anything they can do, but beware they'll try to sell you the latest version too. Make sure you know why you want 1.0 working first, be it nostalgia or some other purpose, and just tell them that and see what happens. You have your bad floppy that you can send them if they need some verification. They may have a stash of old floppies somewhere that they'll access for you. Who knows.